Movement of a magnet can impact its operation. Rotation, in particular, can cause coils of the magnet to move in unwanted or unexpected ways. In some cases, even very small movements—e.g., on the sub-millimeter level—can affect the magnitude and/or the shape of a magnetic field produced by the magnet. For applications, such as radiation therapy, that require accurate and predictable magnetic fields, changes in the magnetic field produced by unwanted or unexpected coil movement can be consequential.